Utilization of darbepoetin alfa in relation to cancer patients' hemoglobin levels.

OBJECTIVE: Previous labeling and guidelines recommended initiating erythropoiesis agents (ESAs) for chemotherapy-induced anemia (CIA) at hemoglobin (Hb) levels < 11 g/dL, maintaining near 12 g/dL, and withholding at > or = 13 g/dL. This study analyzed adherence with recommendations in administration of darbepoetin (DA) to cancer patients.

DESIGN, SETTING, AND PARTICIPANTS: Retrospective analysis of Hb levels at which DA was administered using Varian electronic medical records (EMRs). The dataset comprises 141 694 cancer patients from 82 sites across 13 states. The study evaluated DA administrations with respect to recorded Hb for 8988 patients from 1/1/05 to 5/31/07.

MAIN OUTCOME MEASURES: Proportion of DA administrations at Hb > or = 12 and Hb > or = 13 g/dL. Hb level was analyzed for all administrations, stratified by year and anemia type (CIA, anemia-of-cancer, and myelodysplastic syndrome).

RESULTS: There were 51 111 DA administrations with Hb results. The proportion of administrations at Hb > or = 12 g/dL was 7.2% and at Hb > or = 13 g/dL was 0.6%, and for CIA 6.9%/0.6%, anemia of cancer (AOC) 8.8%/0.8%, and myelodysplastic syndrome (MDS) 6.5%/0.6%. The proportion of all DA administrations at Hb > or = 12 g/dL and > or = 13 g/dL declined from 8.6% to 5.3% (p < 0.0001) and from 0.7% to 0.4% (p < 0.0007), respectively during 1/1/05-5/31/07.

CONCLUSIONS: In this population, DA administration at Hb > or = 12 g/dL and Hb > or = 13 g/dL occurred in 7.2% and 0.6% of administrations, respectively, a approximately 93% adherence rate with recommendations. Further research is required to understand dose titrations at Hb 12-13 g/dL, and whether similar patterns are observed for other ESAs, and in other practice settings. This study provides context for the debate regarding the utilization, benefits and risks of ESAs in cancer patients.